The present invention relates to lacings for belts, such as conveyor belts, power drive belts, and the like, and in particular to a hook keeper therefor.
Endless belts are used extensively in a wide variety of different commercial and industrial applications. Conveyor belts and power drive belts are particularly prevalent in agricultural equipment, airport baggage conveyor systems, mining conveyors, and many other similar systems.
The ends of such endless belts are typically interconnected by a lacing, which is usually flexible to permit the belt to pass over pulleys. One common type of lacing is illustrated and described in U.S. Pat. Nos. 1,498,275 and 2,068,826, and comprises a plurality of wire-like hooks that have points on opposite legs clenched or embedded in the leading and trailing ends of the belt. The loop ends of the hooks are meshed together, and a pin extends through the meshed loops to interconnect the opposite ends of the belt. Such hook-type lacings provide great flexibility, which compensates for slight misalignment while providing smooth hinge action, and have experienced widespread use and acceptance.
One problem experienced with hook-type lacings is that the outermost hooks tend to separate laterally from the lacing, thereby shifting additional stress onto the remaining hooks. In general, as the lacing wears, the outermost hooks tend to pivot laterally outwardly away from the center of the lacing, and slide off of the connecting pin. This type of deterioration not only increases the strain on the remaining hooks in the lacing, but also exposes the next outermost hook, which is typically located on the trailing side of the belt. Hence, if the belt should engage any type of obstruction, or rub against a belt guide or the like, the hook on the trailing side of the belt can be easily torn or peeled off of the lacing, such that the hooks generally fail in pairs. The load on the remaining hooks ultimately increases to a point where the entire lacing pulls apart or unzips.
The premature failure of hook-type lacings is a particular problem when the belt is under high tension loading. The ends of the belt tend to bow in plan elevation under such circumstances, thereby applying additional stress on the outermost lacing hooks.
Another problem which exacerbates premature lacing failure is the rubbing of the side edges of the belt against belt guides or the like, which can be caused by a variety of situations, such as unsquare belt ends, slight misalignment between the drive and driven pulleys, or non-uniform belt loading. Under such circumstances the belt has a tendency to move transversely off of the pulleys. In order to ensure that the drive belt always remains aligned with the pulleys, belt guides or alignment posts are fixedly mounted in the machine at locations adjacent to the opposite side edges of the belts. Abutment between such alignment posts and the side edges of the drive belt can be very damaging to the lacing, and result in premature failure. Post type belt guides can impart shock loading to the lacing, which is particularly damaging.
One particular example of such problems in hook-type lacings pertains to round hay balers, such as the machine illustrated in the Gehl "Round Baler 1850" brochure identified in the Disclosure Statement. In round hay balers, a plurality of belts are used to compress hay into large, cylindrically shaped bales. The tension in the baling belts is extremely high in order to form very compact bales. A plurality of belt guides and alignment posts are provided at various locations along the serpentine path of belt translation in order to maintain proper lateral positioning of the belts. These two conditions, particularly when experienced in combination, create a rather severe application for the lacings that interconnect the ends of the bale forming belts.